Supercapacitors based on graphene-supported iron nanosheets as negative electrode materials

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Supercapacitors are crucial energy storage devices.
• Developing high-performance electrode materials is key to advancing supercapacitor technology.
• Graphene and metal nanosheets offer unique properties for energy storage.

Purpose of the Study:

• To synthesize a novel iron nanosheet/graphene nanocomposite (C-PGF).
• To evaluate the electrochemical performance of C-PGF for supercapacitor applications.
• To demonstrate the potential of C-PGF in high-energy density asymmetric supercapacitors.

Main Methods:

• Facile synthesis of C-PGF via carbonization of iron ions on polyaniline nanosheet/graphene oxide.
• Characterization of the nanocomposite's structure and properties.
• Fabrication and testing of an asymmetric supercapacitor device (C-PGF//Ni(OH)2/CNTs).

Main Results:

• The C-PGF nanocomposite exhibits an ultrahigh capacitance of approximately 720 F g(-1) in 6 M KOH.
• The asymmetric supercapacitor achieved an energy density of approximately 140 Wh kg(-1).
• The supercapacitor demonstrated acceptable cycling stability with 78% retention after 2000 cycles.

Conclusions:

• The synergistic effect of iron and graphene nanosheets leads to superior electrochemical performance.
• The developed supercapacitors show energy density comparable to lithium-ion batteries.
• This work provides a guideline for designing advanced next-generation supercapacitors for various applications.